title: Asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines: an expeditious route to chiral δ-aminoesters and piperidones.
abstract: The asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 complexes in the presence of 4 Å MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.
authors.affiliation: Department de Química Orgànica-Facultat de Química, Universitat de València, C/Dr. Moliner 50, 46100 Burjassot, València (Spain), Fax: (+34) 963544328.
authors.forename: Miguel
authors.initials: M
authors.lastname: Espinosa
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Blay
authors.forename: Luz
authors.initials: L
authors.lastname: Cardona
authors.forename: José R
authors.initials: JR
authors.lastname: Pedro
keywords: amino acids; asymmetric catalysis; carbanions; conjugate addition; imino compounds